Medical devices are commonly used to access remote regions of the body for diagnostic, surgical, or therapeutic purposes. In some examples, endoscopes may be inserted through a body lumen to access the colon, esophagus, stomach, urethra, bladder, ureter, kidneys, lungs, bronchi, uterus, and/or or other organs. In other examples, catheters may be inserted through the circulatory system to access treatment sites near the heart, or through the urinary system to access sites near the kidney.
Body lumens come in various shapes and sizes. Some medical devices may be introduced into the body through a large body lumen (such as the urethra) and passed through a narrower body lumen (such as a ureter) to reach a treatment site (such as the interior of a kidney). Some body lumens are naturally formed to curve, loop around, or even wind back, while other body lumens are surgically formed by tunneling tools and, thus, irregularly shaped. A device with a steerable shaft is advantageous when negotiating any of these body lumens. Such a device should be flexible enough to permit steering, yet rigid enough to prevent buckling.
Wires may be used to steer the device through a body lumen. In some devices, the wires are routed through the interior of the device, potentially increasing its outer diameter. Because the device may be pushed through the body lumen, even small increases in the outside diameter of the device may complicate access to some treatments sites by preventing passage of the device through a preferred body lumen. In other devices, the wires may be routed through a structure inside of the device, such as a sleeve, which may further increase the outer diameter of the device. These structures also may decrease the usable interior space of the device. Given that most body lumens are narrow, even small decreases in the usable interior space of the device may limit its usefulness by, for example, reducing the size of one or more working lumens extending through the device, and/or the type of tool usable therewith.
The articulating devices and methods described herein may rectify some of the deficiencies described above, and address other aspects of the prior art.